Data from: The monophyly of Euparkeriidae (Reptilia: Archosauriformes) and the origins of Archosauria: a revision of Dorosuchus neoetus from the Mid-Triassic of Russia

Euparkeria capensis is resolved as the sister taxon to crown Archosauria
in many cladistic phylogenies and provides a key outgroup which may
approximate the ancestral archosaur morphology. Several other taxa have
been referred to the family Euparkeriidae, but the monophyly of this taxon
remains doubtful and largely untested. In order to test this monophyly,
the archosauriform and putative euparkeriid Dorosuchus neoetus from the
Mid-Triassic of Russia is reexamined in light of recent work on the
evolution of stem archosaurs. Dorosuchus neoetus is found to possess a
number of morphological features that place it close to Archosauria,
including a sigmoidal femur with a clear attachment region for the m.
caudifemoralis musculature, but no unambiguous archosaurian apomorphies.
Dorosuchus neoetus is included for the first time in a numerical cladistic
analysis, and is recovered as the sole sister taxon to
Archosauria+Phytosauria. A monophyletic Euparkeriidae including D. neoetus
and E. capensis is slightly less parsimonious. In addition, a mandible and
pterygoid that were previously referred to D. neoetus subsequent to the
original description of the species are also included separately within
the phylogenetic analysis, and are recovered within crown Archosauria,
possibly raising questions as to their correct taxonomic referral.
However, this phylogenetic placement is based primarily on the absence of
palatal teeth, but the presence or absence of palatal teeth exhibits
considerable homoplasy within Archosauriformes. Based on other aspects of
their morphology, we do not reject the referral of these elements to D.
neoetus.